Synthesis, Spectral And Electrochemical Characterization Of Non-Aggregating Alpha-Substituted Vanadium(Iv)-Oxo Phthalocyanines

Two alpha-substituted vanadium-oxo phthalocyanines, [(OC6H3(t-Bu)(2))(4)Pc]VO and [(OC8H17)(4)Pc]VO, where OC6H3(t-Bu)(2) is 2,4-di-tert-butylphenoxy and OC8H17 is 2,2,4-tri-methyl-3-pentoxy, were synthesized and characterized by elemental analysis, mass spectrometry, UV-visible, IR, ESR spectroscopy and electrochemistry. Both complexes have good solubility and do not aggregate in polar or non-polar solvents. Three reductions and two oxidations can be observed in DMF containing 0.2 M TBAP. A HOMO-LUMO gap of similar to 1.4 V is seen for both complexes. The first two one-electron reductions and first oxidation are reversible diffusion controlled electrode processes under the given experimental conditions. The effects of solvent and phthalocyanine macrocycle substituents on the Q bands of the electronic absorption spectra are discussed. Copyright (C) 2005 Society of Porphyrins & Phthalocyanines.